How to keep all the islands facing the right direction (UV)?
In 3D-View-Window press N for opening Properties.

Under "Mesh Display" you find "NORMALS:" press the "Face" Symbol. If you now go with your mesh to the Edit-Mode you see little lines coming out of the center of each face (These lines show the Normal direction). With "Size" in Properties-Panel you can change the Length of the these lines. 

Now choose all your faces and open Tool-Shelf by pressing "T". Under "Shading" you find "Recalculate". All Faces should now look in the same Direction. If any of your faces should not, select these faces manually and press "Flip Direction".

"Recalculate" could not work perfectly when your faces are not connected (Island-faces?????)